Commonly used database field types are as follows:
Field Type Chinese Description Limit Condition Other Description CHAR Fixed Length Strings Maximum Length 2000 BYtes VARCHAR2 Variable Length String Maximum Length 4000 Bytes Maximum Length 749NCHAR The fixed length string of fixed length according to the character set 2000 BYtes nvarchar2 Depending on the character set, the variable length string, the maximum length of 4000 Bytes Date (Day-Ye) DD-MM-YY (HH-MI-SS) has been strictly tested, and there is no large stroke of the large string. Length 2G (231-1) sufficient to store large-end works RAW fixed length binary data maximum length 2000 BYTES Multimedia image sound, etc. Long Raw variable length binary data maximum length 2G binary data maximum length 4G Clob characters Data Maximum length 4G nclob Depending on the character set Character data maximum length 4G bfile stored in the binary data outside the database, the unique line number recorded in the ROWID data table 10 bytes ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. ********. *. **** Format, * is the unique line number recorded in 0 or 1NROWID binary data table 4000 BytesNumber (p, s) digital type P is an integer bit, S is a small digit Decimal (P, s) digital type P is an integer bit, S is a small integer Float floating point number type Number (38), double precision REAL real type Number (63), high precision